Method of installing tubular rivets



March 11, 1952 R. s. COLLEY 2,588,907

METHOD OF INSTALLING TUBULAR RIVETS Filed Dec. 1, 1949 JUL 5272275.

Patented Mar. 11, 1952 r METHOD OF INSTALLING TUBULAR HIVETS Russell S.Colley, Cuyahoga Falls; Ohio, assignor to The B. F. Goodrich Company,New York}. N. Y". a. corporation of New York Application December 1,1949', Serial No. 1303 .14

2 Claims.

1 The invention relates to the installing and up-- setting of headedtubular rivets.

Heretofore, internally threaded, tubular rivets provided with pre-formedflat, round, countersunk, or other suitably shaped heads have been usedfor riveted attachments as for joining parts of an airplane wing orother structure. A type of head designedfor a particular use has notbeen suitable for work necessitating other types of heads. This hasresulted in the stocking and use of a wide variety of rivetshavingdifferent shapes of. heads, each best suited for a particular use. Also,this has resulted. in objectionable manufacturing. complications and.even in objectionable shortages at times of a. particular size and kindof. headed rivet.

An. object. of the. invention is. to provide for overcoming; theforegoing. difficulties and other disadvantages of the prior rivets andtheir attachments to the work.

Other objects are to provide an improved number of other standard typeheads; to provide for changing the lower or seating surface of the headsuch that it conformsto the work while the head is beingv shaped duringthe upsetting; to provide for maintaining the lateral extent of thehead. while changing both the upper and the lower surfaces of the rivethead to a different configuration during the upsetting to provide forsimplicity of construction of the apparatus; to

provide for a reduction in the number of kinds of"pre-formed rivetheads; and to provide for convenience of manufacture and installation,and for effectiveness of operation.

These and other objects and advantages of the invention will be apparentfrom the: following description.

In the accompanying drawings which form a part of this specification andin which like numerals are employed to designate, like parts throughoutthe same.

Fig. 1 is a sectional view in elevation of a tool and a headed tubularrivet inassembled relation on the apertured work before the upsettingoper@ ation, and constructed in accordance with and embodying theinvention, parts being broken away,

Fig. 2' is a view like Fig. 1 but showing the tool and the rivet intheirrespective conditions after the upsetting operation;

Fig. 3 is a perspective view from above showing the tool and-rivet ofFig. l and a second rivet in upset condition, and

Fig". 4 is a view like Fig. Z-butshewing a-modifi cation of the tool anda difierent shape of the rivet head resulting therefrom.

The illustrative embodiment of the invention shown in the drawingsincludes a tubular rivet comprising a shank l0 having a seating portionor pre-formed head H which is shaped as shownin Fig. 1, with a seatingsurfacel2 which does not conform to the work [3; and includesaninstalling or upsetting tooll5- having anaxially movable draw rod I4and forming meansor anvil IS.

The rivet shown has the countersunk type of head H and can be usedwithout modification in work with countersunk apertures. In theembodiment of Figs. 1 and 2, however, it isdesired to adapt thecountersunk type of head to conformation with the flat work, shown asapertured parts 2i, 22, during the upsetting operation in order that thecountersunk type of head will be suited for a-wide variety ofapplications and not only cases of countersunk Work.

The rivet to be upset is first engaged detachably with the draw rod,then inserted in the work, as shown in Fig. 1, and next axialcompressive force is applied by the tool tor-the rivetto upset it in thework while: the head H is re-formed by the reactionary force appliedthrough the forming means It to the head, thereby causing bending of:the material of the head and preferably also-cold-working thereof in amanner such as to seat: the seating surface. [2; conformingly againstthe work, and. to shape the head to. the desired form, asshown in. Fig.2', after which the tool and draw rod. are removed from; the installedor upset rivet.

The tubular rivet has an: outwardly collapsible or expansiblc wallportion 11 adjacent the countersunk type of head. for engaging the workand an internally threaded end portion [8 for engaging: the draw rod,and is of ductile material such, for example, as aluminum, brass, andsteel.

The forming. means or anvil, which may be internally threaded at 2.4 forengagement with an externally threaded body 23 of: the tool, has an. endportion 25 presenting a forming face or surface 23 of hardened steel orother suitable ma.- terial harder than that of the rivet, for abuttingen ire-forming the head to a different shape and.

of the material of the head axially toward the work and cold-working andstrain-hardening of the material of the head thus increasing theinherent strength and holding power of the head.

To change the countersunk type of head to one having, for example, afinal rounded shape with the seating surface l2 conformingly against thework, the forming surface 26 is of generally concave shape so that itis, preferably, circumferentially continuous and inwardly andcontinuously curved or arcuate relative to said end, and is of adiameter at its outer peripheral edge not less than that of thecountersunk head to maintain the lateral extent of the headsubstantially uniform. The radius of curvature of the forming surface atits outer peripheral region may be less than that of the curvature atthe inner or central region of such surface to provide greater sharpnessof curvature at the outer peripheral region than at the central region,which arrangement is advantageous to facilitate the desired re-formingof the head, especially progressively, from the outer margin orperipheral edge Ila of the head inwardly thereof and terminating at thebore 10a of the rivet. V The tool has the draw rod [4 disposed in anaxia1 bore 2'! extending centrally through the body 23 and anvil l6,which draw rod is connected to any suitable means in the body forproviding relative axial movement of the draw rod and body 23 to upsetthe rivet. The draw rod projects beyond the forming surface 26 andterminates in an externally threaded end portion 28 for engaging theinternal threads of the end portion [8 of the rivet.

In installing the rivet in the Work. the rivet to be upset is threadedlyengaged at its end portion I8 with the threaded end part of the drawrod, the countersunk type of head being nearest the forming surface 26for abutment with the same, and then the rivet is inserted into the hole20 of the work until the head contacts the work at a part of the headinwardly of its outer margin or edge Ila while the margin Ha is spacedfrom the work, as shown in Fig. 1. The next step is to operate the toolincluding the draw'rod in'a manner such that compressive force isexerted in. an axial direction on the rivet to outwardly collapse orexpand the wall portion I! so as to increase its diameter beyond thediameter of the rivet hole 20 and to form an annular and bulged flangeto clamp the work between the head and the flange. The reactionary forcein the opposite axial direction of the rivet is exerted on thecountersunk head by the forming means including the forming surface 26and produces bending and also cold-working of the material of the head,thereby re-forming the head to a different workconforming shape. Byvirtue of its shape and size, the forming surface exerts the reactionaryforce from the outer peripheral edge Ha inwardly thereof and terminatingat the bore Illa, whereby the head is re-formed conformingly against thework and the outer peripheral edge Ila is depressed against the workwith the material of the head inwardly of the edge Ila raised withrespect to the edge Ila, the lateral extent of the head being maintainedsubstantially uniform while the uppermost region at "lb of the bore inthe top of the head is countersunk and flared outwardly, as shownespecially in Figs. 2 and 3. The re-forming of the head against theinwardly curved forming surface results in changing the seating surfaceso that it seats conformingly against the work and changing thecountersunk type of head to one of the round type of head as shown inFig. 2, for the upset condition of the rivet.

The draw rod is then disengaged from the internally threaded end portion18 and removed from the rivet. The tool I5 is then ready for subsequentuse.

' The modification shown especially in Fig. 4 is like that of Figs. 1, 2and 3, except that the shape of the dished forming surface 30 of theanvil differs from that of the forming surface 26 in that the outerperipheral region at 3| of the surface 30 tapers inwardly relative tothe end of the forming means It and the central region at 32 of thesurface 30 is fiat providing a sectional shape of a truncated cone forreceiving the head of the rivet. When the rivet is upset, the formingsurface 30 bends the material of the head such that the re-formed headhas a final shape of a truncated cone with the seating surface l2constituting the base of the cone and conform-. ing to the work.

The practice described hereinabove makes feasible the utilization of thesame type of pre-headed rivet for work requiring the same or differentshapes of the head, and it provides for the conformance of the seatingsurface of the head to the work, and the working of the head to thedesired final shape. This permits advantageously a reduction in thenumber of kinds of pre-headed rivets to be stocked and manufactured.

Variations may be made without departing from the scope of the inventionas it is defined in the following claims.

I claim:

1. The method of attaching in distortion-resisting work a'rivet having ashank terminating in a head having an outwardly and upwardly flaredunderface not conforming to said work and a top face not conforming to ahead-contacting surface of a tool so that contact of said top face withthe head-contacting surface starts along a peripheral line at the outermargin of the head, with a bore extending through said head into theshank of the rivet to an engaging portion therein and including anexpansible shank portion intermediate the engaging portion and the head,which method comprises the steps of inserting the rivet in an aperturein the work with said expansible shank portion projecting beyond theback of the work and with the entire outer margin of the head initiallyspaced substantially from the front of the work while the material ofthe head at the innermost part of said underface is initially againstthe front of the work with the remainder of said un-- derface initiallyprojecting angularly away from the front of the work, applying pullingforce to the rivet in the axial direction thereof toward the head by adrawing element of the tool inserted through said head'and engaging saidengaging portion so as to bulb outwardly said expansible shank portionagainst the back of the work, and at the same timealtering the originalshape of the head and conforming said underface ofthe head to the frontof the work by applying a reacting force through the head-contactingsurface of the tool to the head initially at said outer margin only andprogressively additively inwardly thereof so as to bend and depress saidouter margin and flex said remainder of the underface about saidinnermost part thereof conformingly against the front of the Work whilecontinuously pressing said innermost part of said underface against thefront of the work and continuing application of the forces until thework is tightly clamped between the head and the bulb.

2. The method of attaching in distortion-resisting work a rivet having ashank terminating in a head having an outwardly and upwardly taperedunderface not conforming to said Work and a top face not conforming to ahead-contacting surface of a tool so that contact of said top face withthe head-contacting surface starts alonga peripheral line at the outermargin of the head, with a bore extending through said head into theshank of the rivet to an internally threaded portion therein spaced fromthe head and including an expansible shank portion intermediate thethreaded portion and the head, which method comprises the steps ofinserting the rivet in an aperture in the work with said expansihleshank portion projecting beyond the back of the Work and with the entireouter margin of the head initially spaced substantially from the frontof the work while the material of said head at the innermost part ofsaid underface is initially against the front of the work with theremainder of said underface initially projecting angularly away from thefront of the work, applying pulling force to the rivet in the axialdirection thereof toward the head through a threaded drawing member ofthe tool inserted through said head into threaded engagement with saidthreaded portion so as to bulb outwardly said expansible shank portionagainst the back of the work, and at the same time altering the originalshape of the head and conforming said underface of the head to the frontof the work by applying a reacting force through the head-contactingsurface of the tool to the head initially at and peripherallycontinuously about said outer margin only and progressively additivelyinwardly and peripherally thereof so as to bend and depress said outermargin and flex said remainder of the underface about said innermostpart thereof conformingly against the front of the work whilecontinuously pressing said innermost part of said underface against thefront of the work and continuing application of the forces until thework is tightl clamped between the head and the bulb.

RUSSELL S. COLLEY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,228,239 Phillips May 29, 19172,047,341 Vaughn July 14, 1936 2,371,452 Lees, Jr Mar. 13, 19452,384,321 Lees, Jr. Sept. 4, 1945 2,386,939 Desmet Oct. 16, 19452,445,067 Hiler July 13, 1948 2,466,811 Huck Apr. 12, 1949

